Electrical components have achieved high reliability that enable using systems to attain high standards of reliability, availability and serviceability. To attain the optimum reliability of which the electrical components are capable, it is necessary to have the more simple, low tech elements of the system also perform with maximum reliability. Among such elements that can malfunction and cause an electronically functional system to fail are connectors that separate or otherwise interrupt circuit connections and thermal cooling systems that may only partially fail, causing system shutdown to prevent system damage or erroneous system operation.
It is undesirable to have a system shutdown if an air circulating component fails or must be removed for service. Thus the cooling apparatus associated with a data processing system should tolerate a partial failure and subsequent removal and replacement of components without interrupting operation or causing a diminished performance of the data processing system. The system must correct for a failed cooling apparatus unit or element without operator or service intervention and must continue uninterrupted functioning when an element of the cooling system is removed for repair or replacement. The control of the cooling apparatus should not only continue operation while tolerating partial failure, but also determine when the apparatus is no longer capable of adequate performance and initiate an orderly shut down prior to compromise of the host system.